Composite wing unmanned aerial vehicle

Abstract

The invention provides a composite wing unmanned aerial vehicle which comprises a fuselage, a fixed wing system and a propeller system, the fixed wing system and the propeller system are arranged on the fuselage, the fixed wing system comprises a pair of fixed wings, the fixed wings extend in the left-right direction of the fuselage, and the fixed wings are arranged in the front-back direction of the fuselage and form a tandem wing structure; an up-and-down distribution relation is formed in the vertical direction; the propeller system comprises a plurality of propellers, and the propellers are evenly distributed on the periphery of the fuselage. The composite-wing unmanned aerial vehicle does not need to be equipped with a control surface of a traditional fixed-wing aircraft, that is, the wings (fixed wings) are not provided with ailerons or flaps, and the empennage is not provided with elevators and rudders, so that the mechanism complexity is reduced, and the system reliability is improved. Pitching, rolling and yawing control of the whole machine is achieved through rotation speed differential motion of the propellers, the control response speed and the control sensitivity are improved, and therefore a flight control system is remarkably simplified.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and more specifically, to a compound-wing UAV. Background Technology

[0002] Currently, the main type of drone capable of vertical takeoff and landing (VTOL) on the market is the multi-rotor drone. Multi-rotor drones generate lift through multiple propellers, overcoming the runway-based takeoff limitation of fixed-wing drones and offering good adaptability to different takeoff and landing sites. However, multi-rotor drones rely entirely on propellers for lift to overcome their own gravity during flight, while also allocating some thrust for attitude adjustment, forward movement, and cruise control. This reliance on propellers for all lift results in low energy efficiency, limiting their range and endurance, making it difficult to perform long-distance missions.

[0003] In existing technologies, to achieve both vertical takeoff and landing (VTOL) and long endurance, most UAVs adopt a VTOL fixed-wing configuration. Common transitional solutions include thrust vector control, rotor tilting, and wing tilting. While these solutions can achieve a smooth transition between VTOL and horizontal cruise, they are structurally complex, involve numerous mechanical transmission systems, have high manufacturing costs, are difficult to maintain, and carry a high risk of mechanical failure. Summary of the Invention

[0004] The purpose of this invention is to provide a compound wing unmanned aerial vehicle with a simple mechanical structure and high reliability.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a compound wing unmanned aerial vehicle (UAV), including a fuselage and a fixed wing system and a propeller system both disposed on the fuselage. The fixed wing system includes a pair of fixed wings, which are disposed in the front and rear directions of the fuselage to form a tandem wing structure and are arranged vertically in an up-down distribution relationship. The propeller system includes multiple propellers, which are evenly distributed around the fuselage.

[0006] In one embodiment, the pair of fixed wings includes a front wing and a rear wing distributed along the front-rear direction of the fuselage, with the front wing located below the highest point of the propeller and the rear wing located above the highest point of the propeller.

[0007] In one embodiment, there is an angular difference between the mounting angles of the two fixed wings.

[0008] In one embodiment, both the front wing and the rear wing extend along the left-right direction of the fuselage, and each of the propellers is located between the two wings along the left-right direction of the fuselage.

[0009] In one embodiment, the wing area of ​​the rear wing is larger than that of the front wing.

[0010] In one embodiment, the fuselage includes a rectangular frame, a pair of first arms are provided on a pair of sides of the rectangular frame, the front wing is connected to the end of the pair of first arms on one side, the rear wing is connected to the end of another pair of first arms on the other side, and a propeller is installed between each of the first arms and the wing.

[0011] In one embodiment, the first arm is inclined to connect with the rectangular frame, and the angle between the first arm and the rectangular frame is 60°.

[0012] In one embodiment, a pair of second arms are provided on the other pair of sides of the rectangular frame. The pair of second arms are connected to the middle of the two sides of the rectangular frame in a one-to-one correspondence and perpendicularly. Each second arm is equipped with a propeller at its end.

[0013] In one implementation, the pitch, roll, or yaw attitude control of the UAV is achieved by changing the speed difference between the propellers.

[0014] In one embodiment, the motor output shaft of each propeller has an angle with the vertical direction, and the angle value is 5~35°.

[0015] The beneficial effects of the technical solution provided by this invention are as follows: the compound-wing UAV of this invention does not require the control surfaces of a traditional fixed-wing aircraft; that is, there are no ailerons or flaps on the wings (i.e., fixed wings), and no elevators or rudders on the tail, reducing the complexity of the mechanism and improving the reliability of the system. The pitch, roll, and yaw control of the entire aircraft are all achieved through the differential rotation speed of the propellers, improving the control response speed and control sensitivity, thereby significantly simplifying the flight control system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below.

[0017] Figure 1 This is a schematic diagram of the structure of a compound-wing unmanned aerial vehicle provided in one embodiment of the present invention; Figure 2 for Figure 1 The side view of the compound-wing UAV shown; Figure 3 for Figure 1 The diagram shows a partial structure of the compound-wing UAV. Figure 4 This is a schematic diagram of the structure of a hinge provided in one embodiment of the present invention; Figure 5This is a schematic diagram of the structure of a boom lock according to an embodiment of the present invention; Figure 6 for Figure 1 The diagram shows the structure of a compound-wing UAV with its wings folded. Detailed Implementation

[0018] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the invention. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention.

[0019] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0020] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "connection" can refer to a direct connection or an indirect connection via intermediate components (elements). The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the following description.

[0021] It should be noted that the concepts of "first" and "second" mentioned in this invention are only used to distinguish between devices, modules or units, and are not intended to limit these devices, modules or units to necessarily be different devices, modules or units, nor are they intended to limit the order or interdependence of the functions performed by these devices, modules or units.

[0022] Please combine Figure 1 and Figure 2 This invention provides a compound-wing unmanned aerial vehicle (UAV), specifically a compound configuration UAV with a multi-rotor providing attitude control and a fixed-wing providing cruise lift. It combines the flexibility of multi-rotor vertical takeoff and landing with the high-efficiency cruise characteristics of fixed-wing long-endurance operation. In the military field, it can be used for long-range reconnaissance, surveillance, and delivery missions in field environments without relying on runways. In the civilian field, it can be applied to medium- and long-distance cargo transportation, emergency rescue, inspection, and logistics delivery in urban environments, demonstrating broad application prospects.

[0023] The compound wing UAV 100 includes a fuselage 10 and a fixed-wing system 40 and a propeller system 30, both of which are located on the fuselage 10. The propeller system 30 is used to provide lift during vertical take-off and landing and hovering of the UAV, while the fixed-wing system 40 is used to provide the main lift during the cruise phase, which greatly reduces energy consumption and thus improves flight endurance and mission radius.

[0024] The fixed-wing system 40 includes a pair of fixed wings that extend along the left-right direction of the fuselage. These fixed wings are positioned forward and backward along the fuselage, forming a tandem wing structure, and are vertically distributed. In this embodiment, one fixed wing is located slightly forward below the fuselage, and the other is located slightly rearward above the fuselage, forming a vertically tandem wing layout.

[0025] The propeller system 30 includes multiple propellers, which are evenly distributed around the fuselage 10 via the arms 20.

[0026] Specifically, the pair of fixed wings includes a front wing 42 and a rear wing 41 distributed along the fuselage's longitudinal direction. The front wing is located below the highest point of the propeller, with the front wing 42 situated in the region below the propeller, placing it in a relatively stable free airflow environment, resulting in stable and efficient lift output. The rear wing is located above the highest point of the propeller, with the rear wing 41 situated in the region above the propeller, within the range of the accelerating wake. This allows the use of wake energy to enhance the synergistic effect of local lift and thrust, thereby significantly improving the overall aerodynamic efficiency and cruise performance. Furthermore, by adjusting the vertical distance between the front and rear wings, the degree of airflow interference experienced by the front and rear wings can be altered, thereby reducing the pitch moment amplitude during cruise.

[0027] Furthermore, the pitching moment decreases when the distance between the forewing and aft wing decreases, and vice versa. When the vertical distance between the two wings decreases, the pitching moment increases slightly; when the vertical distance increases, the pitching moment decreases. Therefore, by coordinating the relative installation positions of the forewing 42 and aft wing 41, their relative vertical installation heights, and their respective angles of attack, the slope of the pitching moment changing with the angle of attack can be made close to zero within a predetermined angle of attack range, under the design cruise speed and corresponding cruise Reynolds number, thus placing the UAV in a critical state between longitudinal static stability and static instability.

[0028] Within the range of angle of attack, when the UAV changes its pitch or tilt attitude, the pitching moments generated by the changes in lift of the front and rear wings cancel each other out, without producing a significant additional aerodynamic pitching moment. The longitudinal attitude of the UAV (such as pitch, roll, or yaw attitude) is mainly adjusted by the thrust difference of the propeller power unit (the thrust difference is determined by the speed difference), thereby achieving a longitudinally neutral and stable state.

[0029] In this state, the drone's pitching or tilting motion is no longer dominated by aerodynamic restoring force, but is mainly achieved by the thrust difference between the up-down or left-right propellers, thus realizing an attitude control method without aerodynamic control surfaces.

[0030] Therefore, the compound-wing UAV of this invention does not require the control surfaces of a traditional fixed-wing aircraft; that is, there are no ailerons or flaps on the wings (i.e., fixed wings), and no elevators or rudders on the tail, reducing the complexity of the mechanism and improving the reliability of the system. The pitch, roll, and yaw control of the entire aircraft are all achieved through the differential rotation speed of the propellers, improving the control response speed and control sensitivity, thereby significantly simplifying the flight control system.

[0031] In one embodiment, there is an angular difference between the installation angles of attack of the two fixed wings. By adjusting the difference in installation angles of attack between the front and rear wings, the front and rear wings can bear a predetermined proportion of lift during cruise operation. By setting different installation angles of attack for the front and rear wings, the lift distribution ratio between the front and rear wings is adjusted through the angle of attack difference, so that the aerodynamic neutral point of the UAV is substantially coincident with the center of gravity during cruise operation.

[0032] In one embodiment, both the front wing 42 and the rear wing 41 extend along the left-right direction of the fuselage, and each of the propellers is located between the two wings along the left-right direction of the fuselage.

[0033] In one embodiment, the wing area of ​​the rear wing is larger than that of the front wing.

[0034] In addition, by adjusting the longitudinal spacing between the front wing 42 and the rear wing 41, the longitudinal aerodynamic neutral point of the UAV can be moved forward or backward along the longitudinal direction of the fuselage to match the position of the UAV's center of gravity.

[0035] In one embodiment, the fuselage includes a rectangular frame, a pair of first arms are provided on a pair of sides of the rectangular frame, the front wing is connected to the end of the pair of first arms on one side, the rear wing is connected to the end of another pair of first arms on the other side, and a propeller is installed between each of the first arms and the wing.

[0036] In one embodiment, the first arm 21 is inclined to connect with the rectangular frame, and the angle between the first arm and the rectangular frame is 60°.

[0037] In one embodiment, a pair of second arms are provided on the other pair of sides of the rectangular frame. The pair of second arms are connected to the middle of the two sides of the rectangular frame in a one-to-one correspondence and perpendicularly. Each second arm is equipped with a propeller at its end, thereby forming a six-rotor propeller system.

[0038] In one embodiment, the motor output shaft of each propeller has an angle with the vertical direction, the angle being 5 to 35°, to adapt to different flight performance requirements.

[0039] Preferably, the angle between the motor output shaft of the propeller and the vertical direction is 19.8°.

[0040] Furthermore, the tilt direction of the pair of propellers on the second arm 22 is the same as the forward and backward direction of the drone, so that when the drone is cruising, the tilt angle of the fuselage 10 is 70.2°. At this time, the pull direction of the two motors on the pair of second arms 22 is horizontal and forward. The two propellers of the pair of second arms 22, together with the fixed wings, can provide the power for the drone to fly, and the drone is most efficient.

[0041] The tilt design of the six propeller motors, in conjunction with the aircraft's pitch angle during level flight, maximizes propeller efficiency. Simultaneously, the tilt configuration provides additional stabilizing torque in crosswinds or gusts, improving wind resistance and flight attitude stability.

[0042] The tilt design of the six propeller motors makes the thrust direction of the drone more horizontal in level flight, enabling a smooth transition between vertical take-off and landing and level flight modes. Attitude and heading control can be achieved by adjusting the thrust and speed difference of each rotor, which helps to improve cruise speed control and energy efficiency.

[0043] Please combine Figures 3 to 6 In one embodiment, the first arm 21 is connected to the rectangular frame via an arm folding assembly, so that the fixed wing can be unfolded or folded relative to the rectangular frame, thereby reducing the size of the drone during storage and transportation, making it convenient to store and carry.

[0044] In one embodiment, the arm folding assembly includes a hinge 15, an arm latch 16, and a screw and nut assembly (not shown, the same below).

[0045] The hinge 15 includes a spindle 151, a hinge piece 152, and an arm folding rod 153. The hinge piece 152 is provided with a first bushing 1521, and the arm folding rod 153 is provided with a second bushing 1531. The two are sleeved on the spindle 151 in an alternating manner. The hinge piece 152 is fixed to the rectangular frame, and the first arm 21 is fixed to the arm folding rod 153. When the wing is deployed, the arm latch 16 is fixed to the rectangular frame from the side of the arm folding rod 153 facing away from the rectangular frame, pressing the arm folding rod 153 tightly against the rectangular frame. The screw and nut assembly is used to fix the arm latch 16 to the rectangular frame.

[0046] The arm folding rod 153 is provided with an arm mounting block 1532 near both ends. The arm mounting block 1532 has an arm fixing hole group 15321. The angle between the line connecting each arm fixing hole group and the side of the rectangular frame is 60°.

[0047] In one embodiment, the end of the folding arm 153 is provided with a first pressing slope 1533, and the arm latch 16 includes a fixed end 161 and a pressing end 162. The pressing end is perpendicularly connected to the fixed end, and the pressing end 162 is provided with a second pressing slope 1621. When the arm latch is fixedly pressed against the folding arm 153 by the rectangular frame, the second pressing slope 1621 and the first pressing slope 1533 are engaged by an inclined surface.

[0048] Preferably, the fixed end 161 has a locking hole 1611 for the screw to pass through. The screw and nut assembly consists of a screw and a hand-tightening nut fitted onto the screw. The rectangular frame has a locking mounting hole at a position corresponding to the locking hole 1611, and the locking mounting hole is a threaded hole that mates with the screw thread. When the fixed wing needs to be folded, first loosen the hand-tightening nut by hand, and the arm lock can be removed. The arm folding rod 153 can then rotate around the hinge core to fold up and down, thus eliminating the need for tools and facilitating transportation after folding. When the fixed wing needs to be unfolded, unfold the arm folding rod, press the arm lock onto both ends of the arm folding rod, and finally tighten the hand-tightening nut to complete the unfolding process.

[0049] In other embodiments, the arm folding rod 153 can be connected to the rectangular frame by a threaded connector, quick-lock, or binding, so that the arm folding rod can be close to the rectangular frame to keep the wing in the deployed state or separated from the rectangular frame for the arm to fold relative to the rectangular frame.

[0050] Preferably, the folding arm 153 is provided with a weight reduction groove 1534, which extends along the length of the folding arm 153 to reduce the weight of the folding arm 153, thereby avoiding increasing the weight of the drone and ensuring the flight time.

[0051] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions as those in the present invention.

[0052] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A compound-wing unmanned aerial vehicle (UAV), comprising a fuselage and a fixed-wing system and a propeller system both disposed on the fuselage, characterized in that, The fixed-wing system includes a pair of fixed wings, which are respectively located in the front and rear directions of the fuselage and form a tandem wing structure, and are distributed vertically in an up-down relationship. The propeller system includes multiple propellers, which are evenly distributed around the fuselage.

2. The compound-wing UAV according to claim 1, characterized in that, The pair of fixed wings includes a front wing and a rear wing distributed along the front-rear direction of the fuselage. The front wing is located below the highest point of the propeller, and the rear wing is located above the highest point of the propeller.

3. The compound-wing UAV according to claim 2, characterized in that, There is an angular difference between the installation angles of the two fixed wings.

4. The compound-wing UAV according to claim 2, characterized in that, Both the fore wing and the rear wing extend along the left and right direction of the fuselage, and each of the propellers is located between the two wings along the left and right direction of the fuselage.

5. The compound-wing UAV according to claim 4, characterized in that, The rear wing has a larger wing area than the front wing.

6. The compound-wing UAV according to claim 2, characterized in that, The fuselage includes a rectangular frame, with a pair of first arms on one pair of sides of the rectangular frame. The front wing is connected to the end of the pair of first arms on one side, and the rear wing is connected to the end of another pair of first arms on the other side. A propeller is installed between each first arm and the wing.

7. The compound-wing UAV according to claim 6, characterized in that, The first arm is inclined to connect with the rectangular frame, and the angle between the two arms is 60°.

8. The compound-wing UAV according to claim 7, characterized in that, The other pair of sides of the rectangular frame are provided with a pair of second arms, which are connected vertically to the middle of the two sides of the rectangular frame, and each second arm is equipped with a propeller at its end.

9. The compound-wing UAV according to claim 8, characterized in that, The pitch, roll, or yaw attitude control of a drone is achieved by changing the speed difference between the propellers.

10. The compound-wing UAV according to claim 9, characterized in that, Each propeller motor output shaft has an angle with the vertical direction, and the angle value is 5~35°.

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